/* jslint node: true */
'use strict';

//  ENiGMA½
var MCIViewFactory  = require('./mci_view_factory.js').MCIViewFactory;
var menuUtil        = require('./menu_util.js');
var asset           = require('./asset.js');
var ansi            = require('./ansi_term.js');

//  deps
var events          = require('events');
var util            = require('util');
var assert          = require('assert');
var async           = require('async');
var _               = require('lodash');
var paths           = require('path');

exports.ViewController      = ViewController;

var MCI_REGEXP  = /([A-Z]{2})([0-9]{1,2})/;

function ViewController(options) {
    assert(_.isObject(options));
    assert(_.isObject(options.client));

    events.EventEmitter.call(this);

    var self            = this;

    this.client         = options.client;
    this.views          = {};   //  map of ID -> view
    this.formId         = options.formId || 0;
    this.mciViewFactory = new MCIViewFactory(this.client);  //  :TODO: can this not be a singleton?
    this.noInput        = _.isBoolean(options.noInput) ? options.noInput : false;
    this.actionKeyMap   = {};

    //
    //  Small wrapper/proxy around handleAction() to ensure we do not allow
    //  input/additional actions queued while performing an action
    //
    this.handleActionWrapper = function(formData, actionBlock, cb) {
        if(self.waitActionCompletion) {
            if(cb) {
                return cb(null);
            }
            return; //  ignore until this is finished!
        }

        self.client.log.trace( { actionBlock }, 'Action match' );

        self.waitActionCompletion = true;
        menuUtil.handleAction(self.client, formData, actionBlock, (err) => {
            if(err) {
                //  :TODO: What can we really do here?
                if('ALREADYTHERE' === err.reasonCode) {
                    self.client.log.trace( err.reason );
                } else {
                    self.client.log.warn( { err : err }, 'Error during handleAction()');
                }
            }

            self.waitActionCompletion = false;
            if(cb) {
                return cb(null);
            }
        });
    };

    this.clientKeyPressHandler = function(ch, key) {
        //
        //  Process key presses treating form submit mapped keys special.
        //  Everything else is forwarded on to the focused View, if any.
        //
        var actionForKey = key ? self.actionKeyMap[key.name] : self.actionKeyMap[ch];
        if(actionForKey) {
            if(_.isNumber(actionForKey.viewId)) {
                //
                //  Key works on behalf of a view -- switch focus & submit
                //
                self.switchFocus(actionForKey.viewId);
                self.submitForm(key);
            } else if(_.isString(actionForKey.action)) {
                const formData = self.getFocusedView() ? self.getFormData() : { };
                self.handleActionWrapper(
                    Object.assign( { ch : ch, key : key }, formData ),  //  formData + key info
                    actionForKey);          //  actionBlock
            }
        } else {
            if(self.focusedView && self.focusedView.acceptsInput) {
                self.focusedView.onKeyPress(ch, key);
            }
        }
    };

    this.viewActionListener = function(action, key) {
        switch(action) {
            case 'next' :
                self.emit('action', { view : this, action : action, key : key });
                self.nextFocus();
                break;

            case 'accept' :
                if(self.focusedView && self.focusedView.submit) {
                    //  :TODO: need to do validation here!!!
                    var focusedView = self.focusedView;
                    self.validateView(focusedView, function validated(err, newFocusedViewId) {
                        if(err) {
                            var newFocusedView = self.getView(newFocusedViewId) || focusedView;
                            self.setViewFocusWithEvents(newFocusedView, true);
                        } else {
                            self.submitForm(key);
                        }
                    });
                    //self.submitForm(key);
                } else {
                    self.nextFocus();
                }
                break;
        }
    };

    this.submitForm = function(key) {
        self.emit('submit', this.getFormData(key));
    };

    this.getLogFriendlyFormData = function(formData) {
        var safeFormData = _.cloneDeep(formData);
        if(safeFormData.value.password) {
            safeFormData.value.password = '*****';
        }
        if(safeFormData.value.passwordConfirm) {
            safeFormData.value.passwordConfirm = '*****';
        }
        return safeFormData;
    };

    this.switchFocusEvent = function(event, view) {
        if(self.emitSwitchFocus) {
            return;
        }

        self.emitSwitchFocus = true;
        self.emit(event, view);
        self.emitSwitchFocus = false;
    };

    this.createViewsFromMCI = function(mciMap, cb) {
        async.each(Object.keys(mciMap), (name, nextItem) => {
            const mci   = mciMap[name];
            const view  = self.mciViewFactory.createFromMCI(mci);

            if(view) {
                if(false === self.noInput) {
                    view.on('action', self.viewActionListener);
                }

                self.addView(view);
            }

            return nextItem(null);
        },
        err => {
            self.setViewOrder();
            return cb(err);
        });
    };

    //  :TODO: move this elsewhere
    this.setViewPropertiesFromMCIConf = function(view, conf) {

        var propAsset;
        var propValue;

        for(var propName in conf) {
            propAsset = asset.getViewPropertyAsset(conf[propName]);
            if(propAsset) {
                switch(propAsset.type) {
                    case 'config' :
                        propValue = asset.resolveConfigAsset(conf[propName]);
                        break;

                    case 'sysStat' :
                        propValue = asset.resolveSystemStatAsset(conf[propName]);
                        break;

                        //  :TODO: handle @art (e.g. text : @art ...)

                    case 'method' :
                    case 'systemMethod' :
                        if('validate' === propName) {
                            //  :TODO: handle propAsset.location for @method script specification
                            if('systemMethod' === propAsset.type) {
                                //  :TODO: implementation validation @systemMethod handling!
                                var methodModule = require(paths.join(__dirname, 'system_view_validate.js'));
                                if(_.isFunction(methodModule[propAsset.asset])) {
                                    propValue = methodModule[propAsset.asset];
                                }
                            } else {
                                if(_.isFunction(self.client.currentMenuModule.menuMethods[propAsset.asset])) {
                                    propValue = self.client.currentMenuModule.menuMethods[propAsset.asset];
                                }
                            }
                        } else {
                            if(_.isString(propAsset.location)) {
                                // :TODO: clean this code up!
                            } else {
                                if('systemMethod' === propAsset.type) {
                                    //  :TODO:
                                } else {
                                    //  local to current module
                                    var currentModule = self.client.currentMenuModule;
                                    if(_.isFunction(currentModule.menuMethods[propAsset.asset])) {
                                        //  :TODO: Fix formData & extraArgs... this all needs general processing
                                        propValue = currentModule.menuMethods[propAsset.asset]({}, {});//formData, conf.extraArgs);
                                    }
                                }
                            }
                        }
                        break;

                    default :
                        propValue = conf[propName];
                        break;
                }
            } else {
                propValue = conf[propName];
            }

            if(!_.isUndefined(propValue)) {
                view.setPropertyValue(propName, propValue);
            }
        }
    };

    this.applyViewConfig = function(config, cb) {
        let highestId = 1;
        let submitId;
        let initialFocusId = 1;

        async.each(Object.keys(config.mci || {}), function entry(mci, nextItem) {
            const mciMatch = mci.match(MCI_REGEXP); //  :TODO: How to handle auto-generated IDs????
            if(null === mciMatch) {
                self.client.log.warn( { mci : mci }, 'Unable to parse MCI code');
                return;
            }

            const viewId = parseInt(mciMatch[2]);
            assert(!isNaN(viewId), 'Cannot parse view ID: ' + mciMatch[2]); //  shouldn't be possible with RegExp used

            if(viewId > highestId) {
                highestId = viewId;
            }

            const view = self.getView(viewId);

            if(!view) {
                return nextItem(null);
            }

            const mciConf = config.mci[mci];

            self.setViewPropertiesFromMCIConf(view, mciConf);

            if(mciConf.focus) {
                initialFocusId = viewId;
            }

            if(true === view.submit) {
                submitId = viewId;
            }

            nextItem(null);
        },
        err => {
            //  default to highest ID if no 'submit' entry present
            if(!submitId) {
                const highestIdView = self.getView(highestId);
                if(highestIdView) {
                    highestIdView.submit = true;
                }
            }

            return cb(err, { initialFocusId : initialFocusId } );
        });
    };

    //  method for comparing submitted form data to configuration entries
    this.actionBlockValueComparator = function(formValue, actionValue) {
        //
        //  For a match to occur, one of the following must be true:
        //
        //  *   actionValue is a Object:
        //      a)  All key/values must exactly match
        //      b)  value is null; The key (view ID or "argName") must be present
        //          in formValue. This is a wildcard/any match.
        //  *   actionValue is a Number: This represents a view ID that
        //      must be present in formValue.
        //  *   actionValue is a string: This represents a view with
        //      "argName" set that must be present in formValue.
        //
        if(_.isUndefined(actionValue)) {
            return false;
        }

        if(_.isNumber(actionValue) || _.isString(actionValue)) {
            if(_.isUndefined(formValue[actionValue])) {
                return false;
            }
        } else {
            /*
                :TODO: support:
                value: {
                    someArgName: [ "key1", "key2", ... ],
                    someOtherArg: [ "key1, ... ]
                }
            */
            var actionValueKeys = Object.keys(actionValue);
            for(var i = 0; i < actionValueKeys.length; ++i) {
                var viewId = actionValueKeys[i];
                if(!_.has(formValue, viewId)) {
                    return false;
                }

                if(null !== actionValue[viewId] && actionValue[viewId] !== formValue[viewId]) {
                    return false;
                }
            }
        }
        return true;
    };

    if(!options.detached) {
        this.attachClientEvents();
    }

    this.setViewFocusWithEvents = function(view, focused) {
        if(!view || !view.acceptsFocus) {
            return;
        }

        if(focused) {
            self.switchFocusEvent('return', view);
            self.focusedView = view;
        } else {
            self.switchFocusEvent('leave', view);
        }

        view.setFocus(focused);
    };

    this.validateView = function(view, cb) {
        if(view && _.isFunction(view.validate)) {
            view.validate(view.getData(), function validateResult(err) {
                var viewValidationListener = self.client.currentMenuModule.menuMethods.viewValidationListener;
                if(_.isFunction(viewValidationListener)) {
                    if(err) {
                        err.view = view;    //  pass along the view that failed
                    }

                    viewValidationListener(err, function validationComplete(newViewFocusId) {
                        cb(err, newViewFocusId);
                    });
                } else {
                    cb(err);
                }
            });
        } else {
            cb(null);
        }
    };
}

util.inherits(ViewController, events.EventEmitter);

ViewController.prototype.attachClientEvents = function() {
    if(this.attached) {
        return;
    }

    var self = this;

    this.client.on('key press', this.clientKeyPressHandler);

    Object.keys(this.views).forEach(function vid(i) {
        //  remove, then add to ensure we only have one listener
        self.views[i].removeListener('action', self.viewActionListener);
        self.views[i].on('action', self.viewActionListener);
    });

    this.attached = true;
};

ViewController.prototype.detachClientEvents = function() {
    if(!this.attached) {
        return;
    }

    this.client.removeListener('key press', this.clientKeyPressHandler);

    for(var id in this.views) {
        this.views[id].removeAllListeners();
    }

    this.attached = false;
};

ViewController.prototype.viewExists = function(id) {
    return id in this.views;
};

ViewController.prototype.addView = function(view) {
    assert(!this.viewExists(view.id), 'View with ID ' + view.id + ' already exists');

    this.views[view.id] = view;
};

ViewController.prototype.getView = function(id) {
    return this.views[id];
};

ViewController.prototype.hasView = function(id) {
    return this.getView(id) ? true : false;
};

ViewController.prototype.getViewsByMciCode = function(mciCode) {
    if(!Array.isArray(mciCode)) {
        mciCode = [ mciCode ];
    }

    const views = [];
    _.each(this.views, v => {
        if(mciCode.includes(v.mciCode)) {
            views.push(v);
        }
    });
    return views;
};

ViewController.prototype.getFocusedView = function() {
    return this.focusedView;
};

ViewController.prototype.setFocus = function(focused) {
    if(focused) {
        this.attachClientEvents();
    } else {
        this.detachClientEvents();
    }

    this.setViewFocusWithEvents(this.focusedView, focused);
};

ViewController.prototype.resetInitialFocus = function() {
    if(this.formInitialFocusId) {
        return this.switchFocus(this.formInitialFocusId);
    }
};

ViewController.prototype.switchFocus = function(id) {
    //
    //  Perform focus switching validation now
    //
    var self        = this;
    var focusedView = self.focusedView;

    self.validateView(focusedView, function validated(err, newFocusedViewId) {
        if(err) {
            var newFocusedView = self.getView(newFocusedViewId) || focusedView;
            self.setViewFocusWithEvents(newFocusedView, true);
        } else {
            self.attachClientEvents();

            //  remove from old
            self.setViewFocusWithEvents(focusedView, false);

            //  set to new
            self.setViewFocusWithEvents(self.getView(id), true);
        }
    });
};

ViewController.prototype.nextFocus = function() {
    let nextFocusView = this.focusedView ? this.focusedView : this.views[this.firstId];

    //  find the next view that accepts focus
    while(nextFocusView && nextFocusView.nextId) {
        nextFocusView = this.getView(nextFocusView.nextId);
        if(!nextFocusView || nextFocusView.acceptsFocus) {
            break;
        }
    }

    if(nextFocusView && this.focusedView !== nextFocusView) {
        this.switchFocus(nextFocusView.id);
    }
};

ViewController.prototype.setViewOrder = function(order) {
    var viewIdOrder = order || [];

    if(0 === viewIdOrder.length) {
        for(var id in this.views) {
            if(this.views[id].acceptsFocus) {
                viewIdOrder.push(id);
            }
        }

        viewIdOrder.sort(function intSort(a, b) {
            return a - b;
        });
    }

    if(viewIdOrder.length > 0) {
        var count = viewIdOrder.length - 1;
        for(var i = 0; i < count; ++i) {
            this.views[viewIdOrder[i]].nextId = viewIdOrder[i + 1];
        }

        this.firstId = viewIdOrder[0];
        var lastId = viewIdOrder.length > 1 ? viewIdOrder[viewIdOrder.length - 1] : this.firstId;
        this.views[lastId].nextId = this.firstId;
    }
};

ViewController.prototype.redrawAll = function(initialFocusId) {
    this.client.term.rawWrite(ansi.hideCursor());

    for(var id in this.views) {
        if(initialFocusId === id) {
            continue;   //  will draw @ focus
        }
        this.views[id].redraw();
    }

    this.client.term.rawWrite(ansi.showCursor());
};

ViewController.prototype.loadFromPromptConfig = function(options, cb) {
    assert(_.isObject(options));
    assert(_.isObject(options.mciMap));

    var self            = this;
    var promptConfig    = _.isObject(options.config) ? options.config : self.client.currentMenuModule.menuConfig.promptConfig;
    var initialFocusId  = 1;    //  default to first

    async.waterfall(
        [
            function createViewsFromMCI(callback) {
                self.createViewsFromMCI(options.mciMap, function viewsCreated(err) {
                    callback(err);
                });
            },
            function applyViewConfiguration(callback) {
                if(_.isObject(promptConfig.mci)) {
                    self.applyViewConfig(promptConfig, function configApplied(err, info) {
                        initialFocusId = info.initialFocusId;
                        callback(err);
                    });
                } else {
                    callback(null);
                }
            },
            function prepareFormSubmission(callback) {
                if(false === self.noInput) {

                    self.on('submit', function promptSubmit(formData) {
                        self.client.log.trace( { formData }, 'Prompt submit');

                        const doSubmitNotify = () => {
                            if(options.submitNotify) {
                                options.submitNotify();
                            }
                        };

                        const handleIt = (fd, conf) => {
                            self.handleActionWrapper(fd, conf, () => {
                                doSubmitNotify();
                            });
                        };

                        if(_.isString(self.client.currentMenuModule.menuConfig.action)) {
                            handleIt(formData, self.client.currentMenuModule.menuConfig);
                        } else {
                            //
                            //  Menus that reference prompts can have a special "submit" block without the
                            //  hassle of by-form-id configurations, etc.
                            //
                            //  "submit" : [
                            //      { ... }
                            //  ]
                            //
                            const menuConfig = self.client.currentMenuModule.menuConfig;
                            let submitConf;
                            if(Array.isArray(menuConfig.submit)) {    //  standalone prompts)) {
                                submitConf = menuConfig.submit;
                            } else {
                                //  look for embedded prompt configurations - using their own form ID within the menu
                                submitConf =
                                    _.get(menuConfig, [ 'form', formData.id, 'submit', formData.submitId ]) ||
                                    _.get(menuConfig, [ 'form', formData.id, 'submit', '*' ]);
                            }

                            if(!Array.isArray(submitConf)) {
                                doSubmitNotify();
                                return self.client.log.debug('No configuration to handle submit');
                            }

                            //  locate any matching action block
                            const actionBlock = submitConf.find(actionBlock => _.isEqualWith(formData.value, actionBlock.value, self.actionBlockValueComparator));
                            if(actionBlock) {
                                handleIt(formData, actionBlock);
                            } else {
                                doSubmitNotify();
                            }
                        }
                    });
                }

                callback(null);
            },
            function loadActionKeys(callback) {
                if(!_.isObject(promptConfig) || !_.isArray(promptConfig.actionKeys)) {
                    return callback(null);
                }

                promptConfig.actionKeys.forEach(ak => {
                    //
                    //  *   'keys' must be present and be an array of key names
                    //  *   If 'viewId' is present, key(s) will focus & submit on behalf
                    //      of the specified view.
                    //  *   If 'action' is present, that action will be procesed when
                    //      triggered by key(s)
                    //
                    //  Ultimately, create a map of key -> { action block }
                    //
                    if(!_.isArray(ak.keys)) {
                        return;
                    }

                    ak.keys.forEach(kn => {
                        self.actionKeyMap[kn] = ak;
                    });

                });

                return callback(null);
            },
            function drawAllViews(callback) {
                self.redrawAll(initialFocusId);
                callback(null);
            },
            function setInitialViewFocus(callback) {
                if(initialFocusId) {
                    self.switchFocus(initialFocusId);
                }
                callback(null);
            }
        ],
        function complete(err) {
            cb(err);
        }
    );
};

ViewController.prototype.loadFromMenuConfig = function(options, cb) {
    assert(_.isObject(options));

    if(!_.isObject(options.mciMap)) {
        cb(new Error('Missing option: mciMap'));
        return;
    }

    var self            = this;
    var formIdKey       = options.formId ? options.formId.toString() : '0';
    this.formInitialFocusId  = 1;   //  default to first
    var formConfig;

    //  :TODO: honor options.withoutForm

    async.waterfall(
        [
            function findMatchingFormConfig(callback) {
                menuUtil.getFormConfigByIDAndMap(self.client.currentMenuModule.menuConfig, formIdKey, options.mciMap, function matchingConfig(err, fc) {
                    formConfig = fc;

                    if(err) {
                        //  non-fatal
                        self.client.log.trace(
                            { reason : err.message, mci : Object.keys(options.mciMap), formId : formIdKey },
                            'Unable to find matching form configuration');
                    }

                    callback(null);
                });
            },
            function createViews(callback) {
                self.createViewsFromMCI(options.mciMap, function viewsCreated(err) {
                    callback(err);
                });
            },
            /*
            function applyThemeCustomization(callback) {
                formConfig = formConfig || {};
                formConfig.mci = formConfig.mci || {};
                //self.client.currentMenuModule.menuConfig.config = self.client.currentMenuModule.menuConfig.config || {};

                //console.log('menu config.....');
                //console.log(self.client.currentMenuModule.menuConfig)

                menuUtil.applyMciThemeCustomization({
                    name        : self.client.currentMenuModule.menuName,
                    type        : 'menus',
                    client      : self.client,
                    mci         : formConfig.mci,
                    //config        : self.client.currentMenuModule.menuConfig.config,
                    formId      : formIdKey,
                });

                //console.log('after theme...')
                //console.log(self.client.currentMenuModule.menuConfig.config)

                callback(null);
            },
            */
            function applyViewConfiguration(callback) {
                if(_.isObject(formConfig)) {
                    self.applyViewConfig(formConfig, function configApplied(err, info) {
                        self.formInitialFocusId = info.initialFocusId;
                        callback(err);
                    });
                } else {
                    callback(null);
                }
            },
            function prepareFormSubmission(callback) {
                if(!_.isObject(formConfig) || !_.isObject(formConfig.submit)) {
                    callback(null);
                    return;
                }

                self.on('submit', function formSubmit(formData) {
                    self.client.log.trace( { formData }, 'Form submit');

                    //
                    //  Locate configuration for this form ID
                    //
                    const confForFormId =
                        _.get(formConfig, [ 'submit', formData.submitId ]) ||
                        _.get(formConfig, [ 'submit', '*' ]);

                    if(!Array.isArray(confForFormId)) {
                        return self.client.log.debug( { formId : formData.submitId }, 'No configuration for form ID');
                    }

                    //  locate a matching action block, if any
                    const actionBlock = confForFormId.find(actionBlock => _.isEqualWith(formData.value, actionBlock.value, self.actionBlockValueComparator));
                    if(actionBlock) {
                        self.handleActionWrapper(formData, actionBlock);
                    }
                });

                callback(null);
            },
            function loadActionKeys(callback) {
                if(!_.isObject(formConfig) || !_.isArray(formConfig.actionKeys)) {
                    callback(null);
                    return;
                }

                formConfig.actionKeys.forEach(function akEntry(ak) {
                    //
                    //  *   'keys' must be present and be an array of key names
                    //  *   If 'viewId' is present, key(s) will focus & submit on behalf
                    //      of the specified view.
                    //  *   If 'action' is present, that action will be procesed when
                    //      triggered by key(s)
                    //
                    //  Ultimately, create a map of key -> { action block }
                    //
                    if(!_.isArray(ak.keys)) {
                        return;
                    }

                    ak.keys.forEach(function actionKeyName(kn) {
                        self.actionKeyMap[kn] = ak;
                    });

                });

                callback(null);
            },
            function drawAllViews(callback) {
                self.redrawAll(self.formInitialFocusId);
                callback(null);
            },
            function setInitialViewFocus(callback) {
                if(self.formInitialFocusId) {
                    self.switchFocus(self.formInitialFocusId);
                }
                callback(null);
            }
        ],
        function complete(err) {
            if(_.isFunction(cb)) {
                cb(err);
            }
        }
    );
};

ViewController.prototype.formatMCIString = function(format) {
    var self = this;
    var view;

    return format.replace(/{(\d+)}/g, function replacer(match, number) {
        view = self.getView(number);

        if(!view) {
            return match;
        }

        return view.getData();
    });
};

ViewController.prototype.getFormData = function(key) {
    /*
        Example form data:
        {
            id : 0,
            submitId : 1,
            value : {
                "1" : "hurp",
                "2" : [ 'a', 'b', ... ],
                "3" 2,
                "pants" : "no way"
            }

        }
    */
    const formData = {
        id          : this.formId,
        submitId    : this.focusedView.id,
        value       : {},
    };

    if(key) {
        formData.key = key;
    }

    let viewData;
    _.each(this.views, view => {
        try {
            //  don't fill forms with static, non user-editable data data
            if(!view.acceptsInput) {
                return;
            }

            //  some form values may be omitted from submission all together
            if(view.omitFromSubmission) {
                return;
            }

            viewData = view.getData();
            if(_.isUndefined(viewData)) {
                return;
            }

            formData.value[ view.submitArgName ? view.submitArgName : view.id ] = viewData;
        } catch(e) {
            this.client.log.error( { error : e.message }, 'Exception caught gathering form data' );
        }
    });

    return formData;
};